U.S. Pat. No. 5,851,476 discloses a method of manufacturing a sealing bellows for a hinge mechanism in which a rigid preform is made by injection molding in a first workstation, the preform then being transported to a second workstation where it is heated and subjected to deformation so as to form the bellows.
That method is relatively complex to implement because of the preform being transferred from one station to another, and it also suffers from the drawback of being expensive in energy terms because the preform must be heated in the second workstation before being deformed therein.
U.S. Pat. No. 5,490,966 discloses a method of making a bellows by injection molding in a mold. The bellows is extracted from the mold by means of a pneumatic device that is relatively complicated.
Japanese patent application No. JP 3-268919 describes a bellows made by injection molding in a mold. The bellows is molded in its final configuration and presents folds of reduced thickness.